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Quadrature encoder for linear or rotary position

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Does FlexLogger currently have any provision for recording linear or rotary position via quadrature encoders? I have tried both 9401 and 9361 cards in a 9174 chassis and do not see position as an option. However, linear and angular velocity are available via the standard A and B train X4 decoding.

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Message 1 of 8
Accepted by topic author ejholmgren-emrsn

There is a Preview Feature available for Position encoder measurements. You can enable it by going to File >> Preferences in the Preview Features tab.


Once selected, you can configure Angular Position and Linear Position measurements using the Encoder sensor class. We would welcome any feedback you have on how well this suits your workflow!



Jarrod S.
National Instruments
Message 2 of 8

With this setting enabled I can successfully configure linear and rotary position measurement with a 9361 card (with counters). However, a 9401 (no counters) does not work. Is there any plan to support access to the onboard counters on the chassis in the future?

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Message 3 of 8

Hi, I'm using FL 2019R2 and NI9361 configured to measure Angular Position with a quadrature differential encoder (1024ppr, tracks A-B-Z)

I'd like to let you know that the input terminal Z does not work as intended: even when properly configured (tested OK with a NI-Max task on the same machine and with the same HW) the counter does not reset when triggered by the Z track.

Again everything works as expected on MAX with the same hardware.


Thanks for your support.

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Message 4 of 8


New findings: looks like there's a specific combination of PFI inputs to be used (but not declared) for the Z index to work properly.

I've been able to set it properly with A on PFI0, B on PFI4 anz Z on PFI7. PFI7 is the only PFI that works with this setup (other combinations of A/B on different PFIs not tested).

Again, in Max it IS possible to select ANY (free) PFI for the Z index.



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Message 5 of 8

Thanks for the update! We're looking into this on our side. This information will help. 

Jarrod S.
National Instruments
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Message 6 of 8

Hey ppaga,


We're working on replicating the behavior you are seeing, but right now we see the Z index correctly reset when triggered regardless of the PFI terminal selected. For example, we have PFI0 connected to A, PFI1 connected to B and PFI2 connected to Z.


There are a few details that would help us investigate and replicate what you are seeing:

  • Could you please post a screenshot of the MAX configuration you have working? It will help us best understand your desired setup/ configuration.
  • A screenshot of your FlexLogger configuration popup would be helpful as well.
Briana P.
Sr SW Engineering Manager | NI R&D
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Message 7 of 8

I ran into a similar issue recently. It looks like the 9361 has specific encoder line configurations. This can be seen in the table below from page 23 of the 9361 datasheet.


2019-09-25 08_20_07-NI 9361 Datasheet - National Instruments.png


Austin Stanton

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Message 8 of 8